Bioelectrical impedance analysis during pregnancy and neonatal birth weight

Association Between Pro-inflammatory Cytokine Levels (IL-1β, IL-6, and TNF-α) in Human Colostrum and Maternal Body Composition Components

Background: Obesity is characterized as a low-grade chronic inflammatory state, marked by elevated inflammatory biomarkers. Breast milk (BM) is rich in nutritional elements, vitamins, minerals, immunological factors, and bioactive components. These bioactive components, capable of influencing biological processes, may vary in concentration based on maternal body composition. Research Aim/Question(s): This study aimed to explore the association between pro-inflammatory cytokine levels (interleukin-1 beta [IL-1β], interleukin-6 [IL-6], and tumor necrosis factor-alpha [TNF-α]) in human colostrum and maternal body composition, as analyzed through bioelectrical impedance vector analysis (BIVA). Method: In this cross-sectional study, 117 healthy postpartum participants were included, with each group (normal weight, overweight, and obese) comprising 39 individuals, as classified by BIVA. Colostrum samples were collected within the first 24 hours postpartum. Results: IL-1β levels did not significantly differ across the groups, with concentrations of 69.5 ± 103 pg/mL in normal-weight, 79.7 ± 97.9 pg/mL in overweight, and 68.7 ± 108 pg/mL in obese women. IL-6 levels were significantly higher in the overweight group (55 ± 72.4 pg/mL) than in the normal-weight (48.1 ± 74.1 pg/mL) and obese groups (28.9 ± 36.2 pg/mL) (p = 0.02). Similarly, TNF-α levels were higher in the overweight group, with concentrations of 58.7 ± 74.9 pg/mL, than in the normal-weight group, with concentrations of 38.6 ± 95.4 pg/mL, and 52.6 ± 115 pg/mL in obese women (p = 0.02). Conclusion: This study shows that IL-6 and TNF-α concentrations were statistically higher in the colostrum of overweight women, suggesting that maternal body composition may influence the inflammatory profile of BM.

A Study of Fluid Intake, Hydration Status, and Body Composition of Pregnant Women in Their Third Trimester, and Relationships with Their Infant's Birth Weight in China: A Prospective Cohort Study

BACKGROUND

Water intake and hydration status may potentially influence maternal and child health. However, there is little research regarding this topic.

OBJECTIVES

This study aimed to investigate pregnant women's total fluid intake (TFI) levels, hydration status, and body composition and further explore their relationship with infant birth weight.

METHODS

A 7-day, 24 h fluid intake recorded was applied to determine participants' TFI levels. Morning urine samples were collected and tested to evaluate their hydration status. Maternal body compositions in their third trimester and infant birth weights were measured.

RESULTS

A total of 380 participants completed the study. The TFI was insufficient for pregnant women during their third trimester (median = 1574 mL), with only 12.1% of participants meeting the recommended adequate fluid intake level for pregnant women living in China (1.7 L per day). With the increasing TFI values, the urine osmolality decreased, which showed statistical significance among the four groups (χ2 = 22.637, p < 0.05). The participants displayed a poor hydration status. Meanwhile, the percentage of participants who were in dehydrated status decreased (χ2 = 67.618, p < 0.05), while body water content and basal metabolic rate increased with the increase in TFI levels (χ2 = 20.784, p < 0.05; χ2 = 14.026, p < 0.05). There were positive linear relationships between plain water intake, the basal metabolic rate of pregnant women and their infant birth weight (SE = 0.153, p < 0.05; SE = 0.076, p < 0.05).

CONCLUSIONS

Water intake was insufficient, and poor hydration status was common among pregnant women in China. There may be potential relationships between plain water intake, basal metabolic rate, and infant birth weight.

Association between Maternal Body Composition in Second Trimester and Risk of Fetal Macrosomia: A Population-Based Retrospective Study in China

(1) Background: Female body composition undergoes significant changes to support fetal growth and development during pregnancy. This study investigated the association of maternal body composition in the second trimester and macrosomia and explored whether body-composition-related indicators could be used to predict macrosomia. (2) Methods: This study was conducted in China from December 2016 to December 2021. Women with singleton pregnancies, gestational ages between 37 and 42 weeks, and an absence of pregnancy complications were included. In the second trimester, bioelectric impedance analysis (BIA) was used to measure body-composition-related indicators. Logistic regression analysis was performed to explore the risk factors for macrosomia. The predictive performance of maternal body composition and clinical indicators for macrosomia were assessed using the area under the receiver-operating-characteristics curve (AUC). (3) Results: This retrospective study involved 43,020 pregnant women; we collected 2008 cases of macrosomia. Gravidity, gestational age, body mass index (BMI), gestational weight gain (GWG), total body water, fat mass, fat-free mass (FFM), skeletal muscle mass, and visceral fat level were risk factors for macrosomia (p < 0.05 for all). In the prediction model, the AUC of FFM for predicting macrosomia was the largest (0.742). (4) Conclusions: Body-composition-related indicators associated with macrosomia and body composition measurements in the second trimester can predict the risk of macrosomia, enabling clinicians to implement interventions earlier to reduce adverse perinatal outcomes.

Awareness and interventions to reduce dehydration in pregnant, postpartum women, and newborns in rural Kenya

Extreme heat exposure is associated with adverse outcomes in pregnancy and has the potential to impact maternal, neonatal and child health for a lifetime. In an extremely hot climate, pregnant women face an increased risk of premature birth, stillbirth, low birth weight, congenital anomalies and pre-eclampsia. In low- and middle-income countries (LMICs), socio-demographic and behavioural practices may negatively affect body hydration during high temperatures. The possible causes and consequences of dehydration in the heat are poorly understood and have been little discussed in the literature.Living in a hot climate poses various challenges, including dehydration, where biological mechanisms and insufficient access to water can lead to dehydration in women and children, with consequences for the health of both mothers and children, particularly in relation to breastfeeding habits. During pregnancy, increased metabolic and cardiovascular demands interact with heat exhaustion and reduced availability of fresh water, which can affect the child's growth and development. In this opinion piece, we emphasise the possible causes and impacts of dehydration in extreme heat on the health and well-being of mothers and children. We encourage more research, focused on biology and epidemiology, related to raising awareness and implementing adaptations to reduce the risk of dehydration in pregnant, postpartum women and newborns in the context of climate change-related heat exposure.

Bioelectrical Impedance Vector Analysis (BIVA) for the monitoring of body composition in pregnancy

BACKGROUND/OBJECTIVES

During pregnancy, body composition alterations can be considered as markers of complications and in this context, a non-invasive and low-cost method such as Bioelectrical Impedance Vector Analysis (BIVA), can be employed to monitor such changes. This study aimed at identifying body compartments trend during physiological pregnancy.

SUBJECTS/METHODS

Classic and specific BIVA variables have been measured in a sample of 37 pregnant women approximately every 4 weeks of gestation and once postpartum. Researchers used both longitudinal and cross-sectional approach. The first case included data of women from the 11th to the 15th week along with data from the 28th to the 32nd week of gestation. The cross-sectional approach regarded two more specific moments (11th-12th weeks and 30th-31st weeks) and data within two months postpartum RESULTS: The longitudinal approach showed a significant decrease in classic BIVA variables (R/H, Xc/H, Z/H p < 0.001) and a shortening of the vector, pointing out that TBW and hydration increased significantly. Specific vector length increased significantly, indicating a physiological gain of FM% (p < 0.01). The cross-sectional approach showed lower values of R/H, Xc/H, Z/H between 12th-13th and 30th-31st weeks (p < 0.01), while in the postpartum period values tended to those registered at the beginning of pregnancy. No changes have been found for the phase angle in both approaches, indicating that ECW/ICW ratio remained constant CONCLUSIONS: Among physiological pregnancies, bioelectric values showed a coherent trend and these results represent a first contribution to support routine exams, leading to an early detection of anomalous values potentially correlated to pathologies.

Variation in urine osmolality throughout pregnancy: a longitudinal, randomized-control trial among women with overweight and obesity

PURPOSE

Water needs increase during pregnancy, and proper hydration is critical for maternal and fetal health. This study characterized weekly hydration status changes throughout pregnancy and examined change in response to a randomized, behavioral intervention. An exploratory analysis tested how underhydration during pregnancy was associated with birth outcomes.

METHODS

The Healthy Mom Zone Study is a longitudinal, randomized-control trial intervention aiming to regulate gestational weight gain (GWG) in pregnant women with overweight/obesity (n = 27). Fourteen women received standard of care; 13 women additionally received weekly guidance on nutrition, physical activity, water intake, and health-promoting behaviors. Hydration status was measured weekly via overnight urine osmolality (Uosm) from ~ 8-36 weeks gestation; underhydration was dichotomized (Uosm ≥ 500 mOsm/kg). Gestational age- and sex-standardized birth weight and length z scores and percentiles were calculated. We used mixed-effect and linear regression models to test covariate-adjusted relationships.

RESULTS

No differences existed in Uosm or other characteristics between control and intervention women at baseline. Significant interactions (p = 0.01) between intervention and week of pregnancy on Uosm indicated intervention women maintained lower Uosm, whereas control women had a significant quadratic (inverse-U) relationship and greater Uosm in the second and early third trimesters. Results were consistent across robustness and sensitivity checks. Exploratory analyses suggest underhydration was associated with birth weight, but not length, in opposite ways in the second vs. third trimester.

CONCLUSION

A multi-component behavioral intervention helped women with overweight/obesity maintain better hydration throughout pregnancy. Future studies should confirm birth outcome results as they have important implications for early life nutrition.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03945266; registered May 10, 2019 retrospectively.

The Possibility of Using Bioelectrical Impedance Analysis in Pregnant and Postpartum Women

Pregnancy is a time of significant changes occurring in the composition of a woman’s body in order to provide support for the growth and development of the foetus. Bioelectrical impedance analysis (BIA) is used to assess the body composition and hydration status. This technique represents a non-invasive, reliable, and fast clinical approach, which is well tolerated by patients. A segmental impedance measurement might be advantageous in pregnant women, particularly in late pregnancy. The purpose of this paper is to provide a review of different applications of BIA in pregnant and postpartum women. It seems that BIA has a better prognostic potential for gestational and post-partum outcomes than body mass index. The BIA method can be successfully used to study the effect of excessive gestational weight gain in pregnancy on the development of obstetric complications. Studying the mother’s body composition and correlating it with her energy balance could facilitate the development of dietary recommendations for women. Evaluation of the body composition can provide important clues for diagnosis of gestational diabetes mellitus in pregnant women with a low risk of this disease. BIA is also used as one of the additional tests in assessing the risk of developing gestational hypertension and preeclampsia.

Myo-inositol supplementation to prevent gestational diabetes in overweight non-obese women: bioelectrical impedance analysis, metabolic aspects, obstetric and neonatal outcomes - a randomized and open-label, placebo-controlled clinical trial

This study aims to evaluate the effects of myo-inositol supplementation on gestational diabetes mellitus (GDM) rates and body water distribution in overweight non-obese women. 223 overweight non-obese women pregnant were randomly assigned to the treatment group (2 g of myo-inositol plus 200 µg of folic acid) or to the placebo one (200 µg of folic acid). The treatment lasted until three weeks after delivery. A tetrapolar impedance analyser was used to study body composition. The incidence of GDM was significantly reduced in the myo-inositol group compared with the placebo group. There was a significant increase in TBW, ECW and ICW values in the placebo group compared to the myo-inositol group. We have recorded a significant reduction in the overall incidence of pregnancy-induced hypertension in the myo-inositol group compared with the placebo group. Our results demonstrate the effectiveness of myo-inositol supplementation in preventing GDM in overweight non-obese pregnant women.

Body composition helps: Differences in energy expenditure between pregnant and nonpregnant females

OBJECTIVES

Human pregnancy is associated with important physiological changes that usually increase energetic requirements. However, great variability exists in the costs and mechanisms required to bear pregnancy. Since body mass (BM) and composition are modified during gestation, it is of great interest to compare the influence of BM on energy expenditure (EE) in pregnant and nonpregnant females.

METHODS

BM, body composition, and EE of 77 volunteers (35 pregnant and 42 nonpregnant females) were measured. The pregnant volunteers completed two measurement rounds at 28 and 32 gestation weeks. Differences on the measured parameters were sought, and comparison of regression lines was computed to test how BM affected the EE of the volunteers.

RESULTS

BM and body composition parameters are significantly higher in pregnant females, but EE is not statistically different. Pregnant females have a larger percentage of fat mass, but lower percentage of fat-free mass (FFM). The EE per kg of FFM is similar in both groups. Comparison of regression lines shows that pregnancy does not change the relationship between BM and EE, but for similar BM pregnant females expend less energy than nonpregnant females.

CONCLUSIONS

We propose that their larger percentage of passive body tissues is the reason why pregnant females expend less energy than nonpregnant females of similar BM, without changing the scaling of EE on BM. Thus, pregnancy could not be as energetically constraining as usually assumed, with important consequences for human reproductive ecology.

Measuring maternal body composition by biomedical impedance can predict risk for gestational diabetes mellitus: a retrospective study among 22,223 women

OBJECTIVES

This study aimed to identify which element of body composition measurements taken before 17th week gestation was the strongest risk factor for gestational diabetes mellitus (GDM) in Chinese pregnant women.

DESIGN AND SETTING

A retrospective study was performed using data retrieved from the Electronic Medical Record database of Chongqing Health Center for Women and Children (China) from January 2014 to December 2015.

PARTICIPANTS

A total of 22,223 women were included with singleton pregnancies and no preexisting diabetes who underwent bioelectrical impedance analysis (BIA) before 17 gestational weeks and 75-g OGTT at 24-28 gestational weeks.

RESULTS

The prevalence of GDM from 2014 to 2015 was 27.13% (IADPSG). All indicators of BIA (total body water, fat mass, fat-free mass, percent body fat, muscle mass, visceral fat levels, proteins, bone minerals, basal metabolic rate, lean trunk mass), age, weight and body mass index (BMI) were risk factors that significantly increased the occurrence of GDM (p < .001 for all). Women older than 30 years or with a BMI more than 23, had a significantly higher GDM prevalence (34.89% and 34.77%). After adjusted covariates, visceral fat levels at the third quartile, the ORs of GDM were 1.142 (95% CI 1.032-1.263) in model I and 1.419 (95% CI 1.274-1.581) in model II used the first quartile as reference (p < .05 for both); bone minerals at the third quartile, the ORs of GDM were 1.124 (95% CI 1.020-1.238) in model I and 1.311 (95% CI 1.192-1.442) in model II (p < .05 for both). After adjusted for age, visceral fat levels and bone minerals, OR of GDM for percent body fat more than 28.77% at the third quartile was 1.334 (95% CI 1.201-1.482) in model II (p < .05 for both).

CONCLUSIONS

Visceral fat levels, bone minerals and percent body fat were significantly associated with an increased risk of GDM, providing the reference ranges of visceral fat levels, bone minerals and percent body fat as predictive factors for Chinese women to estimate the risk of GDM by BIA during pregnancy.

Relationship between maternal body composition during pregnancy and infant's birth weight in Nairobi informal settlements, Kenya

Background

Maternal nutrition depletion during pregnancy compromises fetal programming, and is a cause of adverse birth outcomes. Maternal body composition measurement using direct body composition assessment methods such as the deuterium dilution technique provides better prediction of birth outcomes as compared with commonly used techniques like anthropometry. This study assessed body composition of pregnant mothers in urban informal settlements in Nairobi, Kenya, and established the relationship between maternal body composition and infant birth weight.

Methods

Deuterium dilution technique was used to determine body composition, including total body water (TBW), fat-free mass (FFM) and fat mass (FM), among 129 pregnant women who were enrolled into the study in their first or second trimester. Descriptive statistics and regression analysis were applied using Stata V.13.

Results

The mean TBW, FFM and FM were 33.3 L (±4.7), 45.7 kg (±6.5) and 17.01 kg (±7.4), respectively. Both TBW and FFM were significantly related to maternal age and gestation/pregnancy stage during body composition assessment while FM was significantly associated with gestation stage during body composition assessment. TBW and FFM were significantly lower in younger mothers (<20 years) compared with older mothers (≥20 years). The mean birth weight was 3.3 kg±0.42 kg. There was a positive association between infant birth weight and maternal TBW (p=0.031) and FFM (p=0.027), but not FM (p=0.88).

Conclusion

Non-fat components of the body (TBW and FFM) have a positive association with birth weight. Therefore, interventions to improve optimal maternal feeding practices, to enhance optimal gains in FFM and TBW during pregnancy are recommended, especially among young mothers.

Associations between hydration state and pregnancy complications, maternal-infant outcomes: protocol of a prospective observational cohort study

BACKGROUND

Water requirements increases with gestational age. Insufficient water intake causes dehydration, which may adversely affect maternal health and birth outcomes. However, few related studies have been conducted. The purposes are to assess the water intake and hydration state among pregnant women, and to investigate the associations with pregnancy complications and maternal and infant outcomes.

METHODS

A prospective observational cohort study will be applied. A total of 380 pregnant women will be recruited from the First Affiliated Hospital of Hainan Medical University. Hydration biomarkers and health outcomes will be tested during 15~17 weeks' gestation, 20~22 weeks' gestation, 30~32 weeks' gestation, during childbirth and 42 days after childbirth. Daily fluid intake will be collected using a 24-h fluid intake record for 7 consecutive days. A semi-quantified food frequency method will be used to assess food intake and water intake from food. Anthropometric measurement will be taken following standardized processes. Intracellular fluid (ICF) and extracellular fluid (ECF) will be measured using a body composition analyzer. Morning fasting urine and blood osmolality will be tested by laboratory physicians using an osmotic pressure molar concentration meter. Pregnancy complications will be assessed and diagnosed throughout pregnancy and childbirth. Maternal-infant outcomes will be monitored using related indicators and technologies. In order to explore the internal mechanism and interactions from the perspective of endocrine, pregnancy related hormones (estradiol, prolactin, progesterone) and the hydration-related hormones (copeptin) will be tested during pregnancy. A mixed model of repeated measures ANOVA will be analyzed using SAS 9.2.

RESULTS

The results may provide basic data on water intake among pregnant women. The association between hydration state and maternal-infant outcomes will also be explored.

CONCLUSIONS

This preliminary exploratory study findings will fill the gaps in the research on water intake, hydration and maternal health, birth outcomes, provide scientific reference data for updating recommendation on water adequate intake among pregnant women, and provide suggestion for developing water intake interventions.

TRIAL REGISTRATION

The protocol has been registered on the website of Chinese Clinical Trial Registry. The Identifier code is ChiCTR1800019284. The Registry date is 3 November, 2018. Registry name is "Study for the correlation between hydration state and pregnancy complications, maternal and infant outcomes during pregnancy".

MC4R and ENPP1 gene polymorphisms and their implication in maternal and neonatal risk for obesity

The aims of this study were to establish the role of MC4Rrs17782313 and ENPP1rs1044498 gene polymorphisms on pre-pregnancy BMI and the newborn’s status. We performed a cross-sectional study on 185 mothers and their offspring. The groups were divided into: control group- underweight or normal mothers with BMI_initial < 25 kg/m² (n₁ = 134) and study group-overweight/obese mothers with BMI_initial ≥ 25 kg/m² (n₂ = 51). All subjects underwent demographic, anthropometric, paraclinical, bioimpedance and genetic parameters. We found association between initial BMI and gestational weight gain (GWG), and a higher frequency of excessive GWG in overweight/obese women (p = 0.037). Higher values of anthropometric and bioimpedance parameters were observed in overweight/obese versus underweight/normal women. The MC4R rs17782313 and ENPP1 rs1044498 variant genotypes had an increased risk of pre-pregnancy overweight (OR = 1.41; 95% CI:[0.72; 2.78]; OR = 1.34; 95% CI:[0.65; 2.75]). The newborns from mothers with excessive GWG had a higher birth weight (BW) (p = 0.001). Higher MUAC values were noticed in newborns with MC4R rs17782313 wild-type genotype. Also, BW was correlated with GWG status smoking in pregnancy, gestational age and neonatal ENPP1rs1044498 variant genotype (p = 0.026). Our study pointed out the role of MC4R rs17782313 and ENPP1 rs1044498 genotypes in obesity determinisms in mothers and their newborns in correlation with BMI, MUAC, TST and bioimpedance parameters.

Vaspin in Serum and Urine of Post-Partum Women with Excessive Gestational Weight Gain

Background and objectives: Data concerning vaspin in obstetric aspects are limited and conflicting. The aim of the study was to evaluate vaspin concentrations in the serum and urine of women with excessive gestational weight gain (EGWG) in the early post-partum period (i.e., 48 h after delivery), when placental function no longer influences the results. Materials and Methods: The study subjects were divided into two groups of 28 healthy controls and 38 mothers with EGWG. Maternal body composition and hydration status were evaluated by the bioelectrical impedance analysis (BIA) method. Concentrations of vaspin, fatty acid-binding protein 4 (FABP4), leptin, and ghrelin were determined via enzyme-linked immunosorbent assay (ELISA). Results: Serum vaspin levels were lower in the EGWG group, whereas no significant differences were noted between the groups, with regard to the urine vaspin concentrations. In both studied groups, the serum vaspin concentrations correlated positively with the urine FABP4 levels and negatively with gestational weight gain, body mass index gain in the period from pre-pregnancy to 48 h after delivery (ΔBMI), and fat tissue index (FTI). In the multiple linear regression models, the serum vaspin concentrations were positively dependent on the serum FABP4 levels, as well as negatively dependent on triglycerides, FTI, and ΔBMI. Conclusions: Our study revealed that the EGWG mothers were characterized by significantly lower serum vaspin concentrations in the early post-partum period compared with the subjects that had appropriate gestational weight gain. Our observation supports previous hypotheses that vaspin might be used as a marker of lipid metabolism in pregnancy and maternal adipose tissue. Considering the fact that FABP4 is widely referred to as a pro-inflammatory adipokine, further research on the protective role of vaspin seems crucial, especially in the context of its relationship to FABP4.

Fatty Acid-Binding Protein 4-An "Inauspicious" Adipokine-In Serum and Urine of Post-Partum Women with Excessive Gestational Weight Gain and Gestational Diabetes Mellitus

The exact roles of adipokines in the pathogenesis of type 2 diabetes and obesity are still unclear. The aim of the study was to evaluate fatty acid binding protein 4 (FABP4) concentrations in the serum and urine of women with excessive gestational weight gain (EGWG) and gestational diabetes mellitus (GDM) in the early post-partum period, with reference to their laboratory test results, body composition, and hydration status. The study subjects were divided into three groups: 24 healthy controls, 24 mothers with EGWG, and 22 GDM patients. Maternal body composition and hydration status were evaluated by the bioelectrical impedance analysis (BIA) method. Concentrations of FABP4, leptin, and ghrelin were determined via enzyme-linked immunosorbent assay (ELISA). Healthy women were characterized by the lowest serum leptin concentrations and by a negative correlation between the serum and urine FABP4 levels. Serum FABP4 levels were the highest in the GDM group. Serum FABP4 and leptin concentrations correlated positively in the GDM group. The EGWG group had the highest degree of BIA disturbances in the early puerperium and positive correlations between the urine FABP4 and serum leptin and ghrelin concentrations. The physiological and pathological significance of these findings requires further elucidation.

Body fluid volume homeostasis is abnormal in pregnancies complicated with hypertension and/or poor fetal growth

OBJECTIVES

To evaluate body water volumes and cardiac output in each trimester of pregnancies complicated with hypertension and/or poor fetal growth, relative to uncomplicated pregnancy.

METHODS

In this semi-longitudinal cohort study, a standardised non-invasive maternal hemodynamics assessment in first, second or third trimester was performed in 1068 women with uncomplicated pregnancy (UP), 75 with early onset (EPE) and 117 with late onset preeclampsia (LPE), 139 with gestational hypertension (GH), 129 with small for gestational age (SGA) neonates and 43 with essential hypertension (EH). Women with hypertension or SGA were included prior to onset of symptoms or at diagnosis of disease; 46% of women (758/1631) were assessed in ≥ 2 trimesters. Impedance cardiography and spectrum analysis were used to measure cardiac output, total body water (TBW), extracellular (ECW) and intracellular water (ICW). A linear mixed model was used for inter-trimestrial comparison of parity-, age- and BMI-corrected values within and between groups.

RESULTS

For all pregnancies, TBW is higher in each consecutive trimester, mainly due to increasing fraction of ECW (ECW%). Compared to first trimester UP, ECW and ECW% are higher in EPE whereas TBW, ECW and ICW are lower in SGA. Compared to inter-trimestrial differences in UP, abnormal changes for body water volumes are observed in GH, EPE and LPE and for CO in EPE and LPE. Changes in EH are not different from UP.

CONCLUSIONS

This study is the first to show that concomitant gestational changes of ECW and CO are different from UP already in preclinical stages of pregnancies complicated with hypertension and/or poor fetal growth, except EH. This finding highlights the relevance of early gestational assessment of maternal body fluid status in pregnancies at risk for hypertension or poor fetal growth.

Ghrelin in Serum and Urine of Post-Partum Women with Gestational Diabetes Mellitus

Women with a previous history of gestational diabetes mellitus (GDM) have a significantly increased risk of developing type 2 diabetes, obesity, and cardiovascular diseases in the future. The aim of the study was to evaluate ghrelin concentrations in serum and urine in the GDM group in the early post-partum period, with reference to laboratory results, body composition, and hydration status. The study subjects were divided into two groups, that is, 28 healthy controls and 26 patients with diagnosed GDM. The maternal body composition and hydration status were evaluated by the bioelectrical impedance analysis (BIA) method. The concentrations of ghrelin in the maternal serum and urine were determined via enzyme-linked immunosorbent assay (ELISA). The laboratory and BIA results of the mothers with GDM were different from those without GDM. Urine ghrelin positively correlated with serum ghrelin and high-density lipoprotein cholesterol (HDL) levels in healthy mothers. There were direct correlations between urine ghrelin and HDL as well as triglycerides levels in the GDM group. Neither the lean tissue index nor body cell mass index were related to the serum ghrelin concentrations in this group. Only the urine ghrelin of healthy mothers correlated with the fat tissue index. Our results draw attention to urine as an easily available and appropriable biological material for further studies.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

Bioelectrical Impedance Vector Analysis in Healthy Term Infants in the First Three Months of Life in Brazil

OBJECTIVE

Bioelectrical impedance vectorial analysis (BIVA) can be considered a favorable method for evaluation and monitoring of nutritional and hydration status without assumptions regarding body composition or requirement of prediction formulas. The present study aimed to determine bivariate tolerance intervals of the whole-body impedance vector for healthy term infants aged 1 to 3 months.

METHODS

This is a descriptive cross-sectional study. Anthropometric and bioelectrical impedance data (800 mA-50 kHz) were obtained. Bivariate vector analysis was conducted with the resistance-reactance (RXc) graph method. BIVA software was used to construct the graphs.

RESULTS

A total of 150 appropriate for gestational age infants (48.7% boys) who were exclusively breastfed and were 56.4 (SD = 23.1) days of age were studied. RXc tolerance ellipses (50, 75, and 95%) were constructed for boys and girls, but a general reference graph was defined for all infants considering the overlapping of ellipses between the genders. All graphs differed from those in national and foreign studies.

CONCLUSION

New reference tolerance ellipses (95, 75, and 50%) for 1- to 3-month-old infants were constructed, pointing out the need for specific reference values of total body impedance vectors in different regions of Brazil. The RXc tolerance ellipses can be used for clinical practice and provide an easy method to evaluate and monitor body composition and hydration status.

Correlation between maternal body composition and haemodynamic changes in pregnancy: different profiles for different hypertensive disorders

OBJECTIVES

To assess and correlate changes in body composition and haemodynamic function during pregnancy. To identify different haemodynamic profiles based on the onset of hypertensive diseases such as gestational hypertension and preeclampsia.

METHODS

We enrolled 265 healthy, normotensive pregnant women throughout pregnancy (from 6+0 to 36+0weeks). They were subjected to assessment of body composition and haemodynamic function using non-invasive methods. We divided our population in three groups: group A with physiological pregnancy, group B with gestational hypertension and group C with preeclamptic patients.

RESULTS

In patients who developed gestational hypertension we found lower total body water (TBW) percentage, higher Fat Mass (FM), associated with lower Cardiac Output (CO) and higher Total Vascular Resistance (TVR) during the second trimester. In the third trimester we didn't find haemodynamic differences, but a significative increase in extracellular water (ECW) percentage. In patients who developed preeclampsia we found since the first trimester significative higher TVR and hypodynamic circulation, associated with lower FM percentage.

CONCLUSIONS

Assessment of body composition and maternal cardiac function may help to identify earlier in pregnancy, patients with different (mal) adaptations to pregnancy. Women with high TVR, hypodynamic circulation and low fat mass during the first trimester, might be at higher risk to develop preeclampsia. Patients with higher BMI and FM percentage, and increased TVR in the second trimester, might be at risk of gestational hypertension and excessive fluid retention at the end of pregnancy.

Maternal fat free mass during pregnancy is associated with birth weight

Background

The relationship between maternal body compositions and birth weight was not definite. Fat Mass (FM) and Fat Free Mass (FFM) can accurately reflect the maternal body fat compositions and have been considered as better predictors of birth weight. Despite its potential role, no studies have been described the maternal compositions during pregnancy in East Asian women previously. We investigated the correlation between birth weight and Maternal body composition including fat mass (FM) and fat free mass (FFM). To determine whether birth weight is associated with maternal body fat FM and FFM during pregnancy and, if so, which trimester and parameter is more critical in determining birth weight.

Methods

A longitudinal prospective observational study performed, 348, 481 and 321 non-diabetics Han Chinese women with a singleton live birth attending a routine visit in their first, second and third trimesters were recruited. Maternal body composition was measured using segmental multi-frequency bioelectrical impedance analysis. Data of the pre-pregnancy body mass index (BMI), maternal BMI, the gestational weight gain (GWG), and placental and birth weight were collected.

Results

A significant correlation exists between maternal FFM in the process of pregnancy, placental weight, GWG at delivery, and birth weight (P < 0.05). On stepwise multiple linear regression analysis, material’s FFM was the most important factor associated with the birth weight. After adjustment, there was significantly associated with 2.47-fold increase in risk for birth weight more than 4 kg when FFM ≥ 40.76 kg (Upper quartile of participants). The increased maternal age became a protective factor (OR = 0.69) while the increased pre-pregnancy BMI (OR = 1.50) remained predictors to birth weight more than 4 kg.

Conclusions

The change of maternal FFM during pregnancy is independently affected the birth weight.

Longitudinal changes and correlations of bioimpedance and anthropometric measurements in pregnancy: Simple possible bed-side tools to assess pregnancy evolution

PURPOSE

The aim of this study was to assess longitudinal changes of bioimpedance analysis compared with anthropometric measurements in low-risk pregnant woman recruited in the first trimester and to observe possible differences in these indices in women who developed high-risk pregnancies.

MATERIALS AND METHODS

Bioimpedance indices for the three trimesters of pregnancies were calculated separately for uneventful pregnancies delivered of newborns > the 10th centile. These findings were compared with anthropometric measurements. Data of women who developed hypertensive disorders of pregnancy (HDP) or delivered SGA newborns were calculated and compared.

RESULTS

Significantly longitudinal increases were observed in these pregnancies for total body water (TBW), free fat mass, fat mass, and extra-cellular water. These increases were paralleled body mass index (BMI), skinfolds, and waist measurements. The correlations between these two sets of findings were poor. Women who developed HDP with AGA fetuses showed significantly different bioimpedance from normal cases. TBW indices were highly significantly different since the first trimester. In pregnancies delivered of SGA newborns, these indices were opposite of the values observed in patients with HDP-AGA, TBW in these patients was significantly reduced compared with normal pregnancies.

CONCLUSIONS

The bioelectrical impedance is a fast, simple, noninvasive way to assess the TBW content in pregnancy. Our findings are in agreement with the hypothesis that bioimpedance might help to identify early in gestation patients at risk of developing different clinical phenotypes of hypertensive disease of pregnancy and SGA fetuses.

Maternal body fluid composition in uncomplicated pregnancies and preeclampsia: a bioelectrical impedance analysis

OBJECTIVES

Body fluid composition changes during the course of pregnancy and there is evidence to suggest that these changes are different in uncomplicated pregnancies compared to hypertensive pregnancies. The aim of this study was to evaluate the changes in maternal body fluid composition during the course of an uncomplicated pregnancy and to assess differences in uncomplicated pregnancies versus hypertensive pregnancies by using a bio-impedance analysis technique.

STUDY DESIGN

Body fluid composition of each patient was assessed using a multiple frequency bioelectrical impedance analyser. Measurements were performed in 276 uncomplicated pregnancies, 34 patients with gestational hypertension, 35 with late onset preeclampsia and 11 with early onset preeclampsia. Statistical analysis was performed at nominal level α=0.05. A longitudinal linear mixed model based analysis was performed for longitudinal evolutions, and ANOVA with a post-hoc Bonferroni was used to identify differences between groups.

RESULTS

Measurements showed that total body water (TBW), intracellular (ICW) and extracellular water (ECW) and ECW/ICW significantly increase during the course of pregnancy. Late onset preeclampsia is associated with a higher TBW and ECW as compared to uncomplicated pregnancies, the ECW/ICW ratio is higher in preeclamptic patients compared to uncomplicated pregnancies and gestational hypertension, and ICW is not different between groups.

CONCLUSION

Body fluid composition changes differently during the course of uncomplicated pregnancies versus hypertensive pregnancies.

Impact of demographic, genetic, and bioimpedance factors on gestational weight gain and birth weight in a Romanian population: A cross-sectional study in mothers and their newborns: the Monebo study (STROBE-compliant article)

The present study had 2 objectives, first, to investigate possible relationships between increased gestational weight gain and demographic, clinical, paraclinical, genetic, and bioimpedance (BIA) characteristics of Romanian mothers, and second, to identify the influence of predictors (maternal and newborns characteristics) on our outcome birth weight (BW).We performed a cross-sectional study on 309 mothers and 309 newborns from Romania, divided into 2 groups: Group I-141 mothers with high gestational weight gain (GWG) and Group II-168 mothers with normal GWG, that is, control group.The groups were evaluated regarding demographic, anthropometric (body mass index [BMI], middle upper arm circumference, tricipital skinfold thickness, weight, height [H]), clinical, paraclinical, genetic (interleukin 6 [IL-6]: IL-6 -174G>C and IL-6 -572C>G gene polymorphisms), and BIA parameters.We noticed that fat mass (FM), muscle mass (MM), bone mass (BM), total body water (TBW), basal metabolism rate (BMR) and metabolic age (P < 0.001), anthropometric parameters (middle upper arm circumference, tricipital skinfold thickness; P < 0.001/P = 0.001) and hypertension (odds ratio = 4.65, 95% confidence interval: 1.27-17.03) were higher in mothers with high GWG. BW was positively correlated with mothers' FM (P < 0.001), TBW (P = 0.001), BMR (P = 0.02), while smoking was negatively correlated with BW (P = 0.04). Variant genotype (GG+GC) of the IL-6 -572C>G polymorphism was higher in the control group (P = 0.042).We observed that high GWG may be an important predictor factor for the afterward BW, being positively correlated with FM, TBW, BMR, metabolic age of the mothers, and negatively with the mother's smoking status. Variant genotype (GG+GC) of the IL-6 -572C>G gene polymorphism is a protector factor against obesity in mothers. All the variables considered explained 14.50% of the outcome variance.

Bioelectrical impedance analysis in the assessment of pre-eclampsia

PURPOSE

Aim of this prospective investigation was to assess pre-eclampsia by bioelectrical impedance analysis (BIA).

METHODS

A total of 22 pre-eclamptic as well as matched (patients' age, gestational age, parity, gravidity) healthy pregnant women underwent whole body BIA on admission and then, pre-eclamptic patients, every 2 days until childbirth. For all measured BIA single values and their corresponding reference value mean, standard deviation, minimum and maximum were calculated to compare pre-eclamptic women with corresponding reference values. Furthermore a paired t test and an ANOVA of repeated measurements were performed to detect differences of intraindividual measurements. Subsequently an analysis of variance was accomplished to analyse general changes in the course of time of investigated patients, who were measured more than once.

RESULTS

Except for the phase angle, BIA parameters of pre-eclamptic women compared to corresponding reference values were significantly different, suggesting an increase of total body water in pre-eclampsia. Repeated measurements did not reveal statistically significant intra- or interindividual differences in the course of time.

CONCLUSION

Bioelectrical impedance analysis allows differentiating healthy from pre-eclamptic women. Further investigations are needed to analyse if BIA is capable to serve as a prognostic diagnostic tool in the detection of deterioration of pre-eclampsia.

Correlation between birth weight and maternal body composition

OBJECTIVE

To estimate which maternal body composition parameters measured using multifrequency segmental bioelectric impedance analysis in the first trimester of pregnancy are predictors of increased birth weight.

METHODS

Nondiabetic women were recruited after ultrasonographic confirmation of an ongoing singleton pregnancy in the first trimester. Maternal body composition was measured using bioelectric impedance analysis. Multivariable linear regression analysis was performed to identify the strongest predictors of birth weight, with multiple logistic regression analysis performed to assess predictors of birth weight greater than 4 kg.

RESULTS

Data were analyzed for 2,618 women, of whom 49.6% (n=1,075) were primigravid and 16.5% (n=432) were obese based on a body mass index (BMI) of 30 or higher. In univariable analysis, maternal age, BMI, parity, gestational age at delivery, smoking, fat mass, and fat-free mass all correlated significantly with birth weight. In multivariable regression analysis, fat-free mass remained a significant predictor of birth weight (model R=0.254, standardized β=0.237; P<.001), but no relationship was found between maternal fat mass and birth weight. After adjustment for confounding variables, women in the highest fat-free mass quartile had an adjusted odds ratio of 3.64 (95% confidence interval 2.34-5.68) for a birth weight more than 4 kg compared with those in the lowest quartile.

CONCLUSIONS

Based on direct measurements of body composition, birth weight correlated positively with maternal fat-free mass and not adiposity. These findings suggest that, in nondiabetic women, interventions intended to reduce fat mass during pregnancy may not prevent large-for-gestational-age neonates and revised guidelines for gestational weight gain in obese women may not prevent large-for-gestational-age neonates.

LEVEL OF EVIDENCE

: III.

Maternal weight and body composition during pregnancy are associated with placental and birth weight in rural Bangladesh

Placental growth is a strong predictor of fetal growth, but little is known about maternal predictors of placental growth in malnourished populations. Our objective was to investigate in a prospective study the associations of maternal weight and body composition [total body water (TBW) estimated by bioelectrical impedance and fat and fat-free mass derived from upper arm fat and muscle areas (UAFA, UAMA)] and changes in these with placental and birth weights. Within a cluster-randomized trial of maternal micronutrient supplementation, a subsample of 350 women was measured 3 times across gestation. Longitudinal analysis was used to examine independent associations of ∼10-wk measurements and ∼10-20 wk and ∼20-32 wk changes with birth outcomes. Weight, TBW, and UAMA, but not UAFA, at ∼10 wk were each positively and independently associated with placental weight and birth weight (P < 0.05). Of the maternal ∼10-20 wk changes in measurements, only TBW change and placental weight, and maternal weight and birth weight were positively associated (P < 0.05). Gains in weight, TBW, and UAMA from 20 to 32 wk were positively and UAFA gain was negatively associated with placental weight (P ≤ 0.01). Gains in weight and UAMA from 20 to 32 wk were positively associated with birth weight (P ≤ 0.01). Overall, higher maternal weight and measures of fat-free mass at ∼10 wk gestation and gains from 20 to 32 wk are independently associated with higher placental and birth weight.

Maternal nutritional status in early pregnancy is associated with body water and plasma volume changes in a pregnancy cohort in rural Bangladesh

Plasma volume expansion has been associated with fetal growth. Our objective was to examine the associations between maternal nutritional status in early pregnancy and extracellular water (ECW), total body water (TBW), and percentage plasma volume change across pregnancy. In a subsample of 377 pregnant women participating in a cluster-randomized trial of micronutrient supplementation, hemoglobin, hematocrit, and multi-frequency bioelectrical impedance were measured at ~10, 20, and 32 wk of gestation. In early pregnancy, women were short (mean ± SD, 148.9 ± 5.3 cm) and thin (19.5 ± 2.5 kg/m(2)). In mixed-effects multiple regression models, a 1-unit higher BMI at ~10 wk was associated with higher ECW and TBW (0.27 and 0.66 kg per kg/m(2), respectively; P < 0.01) at ~10, ~20, and ~32 wk. Height was also positively associated with ECW and TBW at each time point. Early pregnancy BMI was negatively associated with gains in ECW and TBW (-0.06 and -0.14 kg per kg/m(2), respectively; P < 0.01) from 10 to 20 wk, but not with 20- to 32-wk gains after accounting for weight gain. BMI was positively associated with percentage changes in plasma volume from 20 to 32 wk (0.57% per kg/m(2); P < 0.05). Height was not associated with changes in body water or plasma volume. Women with low BMI and height in early pregnancy have lower ECW and TBW in early, mid, and late pregnancy and lower late pregnancy plasma volume expansion, potentially increasing risk of fetal growth restriction.

The influence of maternal body composition on birth weight

OBJECTIVE

To identify the maternal body composition parameters that independently influence birth weight.

STUDY DESIGN

A longitudinal prospective observational study in a large university teaching hospital. One hundred and eighty-four non-diabetic caucasian women with a singleton pregnancy were studied. In early pregnancy maternal weight and height were measured digitally in a standardised way and the body mass index (BMI) was calculated. At 28 and 37 weeks' gestation maternal body composition was assessed using segmental multifrequency bioelectrical impedance analysis. At delivery the baby was weighed and the clinical details were recorded.

RESULTS

Of the women studied, 29.2% were overweight and 34.8% were obese. Birth weight did not correlate with maternal weight or BMI in early pregnancy. Birth weight correlated with gestational weight gain (GWG) before the third trimester (r=0.163, p=0.027), but not with GWG in the third trimester. Birth weight correlated with maternal fat-free mass, and not fat mass at 28 and 37 weeks gestation. Birth weight did not correlate with increases in maternal fat and fat-free masses between 28 and 37 weeks.

CONCLUSIONS

Contrary to previous reports, we found that early pregnancy maternal BMI in a non-diabetic population does not influence birth weight. Interestingly, it was the GWG before the third trimester and not the GWG in the third trimester that influenced birth weight. Our findings have implications for the design of future intervention studies aimed at optimising gestational weight gain and birth weight.

CONDENSATION

Maternal fat-free mass and gestational weight gain both influence birth weight.

Bioimpedance in pregnant women with preeclampsia

To analyze the direct (resistance and reactance) and indirect (intra and extracellular total body water) BIA parameters in preeclamptic women, 51 healthy pregnant women and 65 preeclamptic women were submmited to bioelectric impedance on the third trimester of gestation. The significance value adopted was 5%. Preeclamptic women showed lower values for R (448 Ω vs. 542 Ω), Rc (40 Ω vs. 53 Ω) and ICW (49.45% vs. 51%) when compared to control group. They also showed higher values for TBW (49% vs. 47%), TBWcor (41.6% vs. 34%) and ECW (50% vs. 47%). Bioelectric impedance allowed differentiating preeclamptic women from health pregnant women, indicating that preeclampsia changes body compartments during pregnancy. This method can help understand the mechanisms involved in preeclampsia and to be a prediction away of preeclampsia.

Volume Control by Using the Body Composition Monitor in a Puerperal Patient on Hemodialysis

Accurate measurement of the volume status in hemodialysis patients is important as it can affect mortality. However, no studies have been conducted regarding volume management in cases where a sudden change of body fluid occurs, such as during puerperium in hemodialysis patients. This report presents a case in which the patient was monitored for her body composition and her volume status was controlled using a body composition monitor (BCM) during the puerperal period. This case suggests that using a BCM for volume management may help maintain hemodynamic stability in patients with a rapidly changing volume status for a short term period, such as during puerperium.

Assessment of change in hydration in women during pregnancy and postpartum with bioelectrical impedance vectors

OBJECTIVE

This study tested the hypothesis that bioelectrical impedance vectors, group and individual, are valid indicators of total body water (TBW) and hydration status in women experiencing fluid gain and loss during and after pregnancy.

METHODS

We measured TBW, assessed with D(2)O dilution, and resistance (R) and reactance (Xc), determined with 800 microA at 50 kHz and standardized for height (H) and plotted on a bivariate (R-Xc) graph, in 15 women, 21-37 y of age, longitudinally before and during pregnancy and postpartum (PP).

RESULTS

Body weight (61.9 +/- 2.3 to 75.5 +/- 2.3 kg) and TBW (31.4 +/- 1.1 to 38.2 +/- 1.1 L) increased (P < 0.05) from before pregnancy to the third trimester of pregnancy and decreased PP (67.0 +/- 2.3 kg and 32.7 +/- 1.1 L, P < 0.05). R/H and Xc/H decreased during pregnancy (P < 0.05, 361 +/- 10 to 318 +/- 10 and 44 +/- 1 to 36 +/- 1 omega/m, respectively) and increased PP (P < 0.05, 355 +/- 10 and 41 +/- 1 Omega/m). Vector length decreased (P < 0.05, 363 +/- 10 to 320 +/- 10 Omega) during pregnancy and increased PP (P < 0.05, 357 +/- 10 Omega). Changes in vector length and TBW during pregnancy and PP were correlated (r = -0.599, P < 0.001). Women with vectors exceeding a 75% tolerance interval had greater TBW gain (10-12 versus 5-6 L) during pregnancy compared with other women with vectors within this tolerance level.

CONCLUSION

These findings indicate that impedance vectors provide quantitative evidence of hydration status during pregnancy and that the impedance vector method is useful in monitoring hydration status in pregnancy.

Relation between maternal body composition and birth weight

In order to establish the relationship between maternal body composition indicators (fat-free mass, fat mass, total body water) and birth weight, a cross-sectional study was designed, based on 196 pairs of mothers and live singleton newborns with gestational age of 37 weeks or more. Immediately after delivery, the mothers were interviewed to obtain information about different birth weight predictors. An analysis of maternal body composition through bioelectric impedance was held. Multiple linear regression was used to measure the effect of each variable on birth weight. The birth weight mean was 3,251 +/- 514 g. Maternal height was 160.44 +/- 6.3 cm, total net weight gain was 5.85 +/- 5.15 kg, fat mass consisted of 15.84 +/- 6.72 kg, and fat-free mass was 50.42 +/- 7.65 kg; total body water was 34.82 +/- 5.61 liters. The model which included total body water and all predictors found to be associated with birth weight in the bivariate analysis (maternal age, gestational age, gender, placenta weight, and placenta weight squared) was found to be the best in explaining the variability of birth weight (R(2) = 45.26%). Fat mass was an important predictor only in the subgroup of women within the low tertile of body mass index. In conclusion, fat-free mass and total body water explained a major proportion of the variability of birth weight in comparison with the mother's weight gain during the pregnancy period, which has already been considered an important predictor of birth weight.

Evaluation of bioimpedance spectroscopy for measurements of body water distribution in healthy women before, during, and after pregnancy

Bioimpedance spectroscopy (BIS) is a technique of interest in the study of human pregnancy because it can assess extracellular (ECW), intracellular (ICW), and total body water (TBW) as ECW plus ICW. The technique requires appropriate resistivity coefficients and has not been sufficiently evaluated during the reproductive cycle. Therefore, in a methodological study, we estimated ECW, ICW, and TBW, by means of BIS, and compared the results with the corresponding estimates obtained by using reference methods. Furthermore, results obtained by means of population-specific resistivity coefficients were compared with results obtained by means of general resistivity coefficients. These comparisons were made before pregnancy, in gestational weeks 14 and 32, as well as 2 wk postpartum in 21 healthy women. The reference methods were isotope and bromide dilution. Average ICW, ECW, and TBW, estimated by means of BIS, were in agreement with reference data before pregnancy, in gestational week 14, and postpartum. The corresponding comparison in gestational week 32 showed good agreement for ICW, whereas estimates by means of BIS were significantly ( P < 0.001) lower than the corresponding reference values for ECW and TBW. Thus the BIS technique, which was based on a model developed for the nonpregnant body, estimated increases in ICW accurately, whereas increases in ECW and TBW tended to be underestimated. Estimates obtained by using population-specific and general resistivity coefficients were very similar. In conclusion, the results indicated that BIS is potentially useful for studies during pregnancy but that further work is needed before it can be generally applied in such studies.

Nifedipine-induced changes in body composition in hypertensive patients at term

BACKGROUND

There are few studies on the effect of nifedipine on fluid homeostasis during pregnancy.

OBJECTIVE

To assess the variation of body composition at term in patients with normal pregnancy and patients with gestational hypertension (GH) treated with nifedipine.

METHODS

Seventeen healthy patients with singleton pregnancies and 12 non-proteinuric patients with gestational hypertension treated with nifedipine were enrolled consecutively from our University Hospital from January 2000 to January 2001. Two evaluations were performed (anthropometric measurements, bioelectric impedance analysis (BIA) at 5, 50 and 100kHz and hematocrit), the first at 36.4+/-3.2 weeks' gestation, the second at 2.1+/-1.6 days of puerperium. The BIA measurements included: fat mass (FM, kg), fat-free mass (FFM, kg), extra-cellular water (ECW, Lt), intra-cellular water (ICW, Lt), total body water (TBW, Lt). Values were analyzed as mean+/-S.D. and statistical analysis was performed by using the Student's t-test for unpaired data.

RESULTS

Birthweights were significantly lower in the gestational hypertensive patients (3472.7+/-266.4g versus 2735.8+/-575.9g, P<0.001). At the first study time, systolic and diastolic blood pressure were significantly higher in the hypertensive patients than in control group, notwithstanding the therapy. Interestingly we found pre-delivery and post-delivery TBW higher in gestational hypertensive patients versus the control patients (44.48+/-9.12Lt versus 36.60+/-5.07Lt, P<0.001 and 40.69+/-4.31Lt versus 37.30+/-4.35Lt, P=0.016, respectively). TBW loss after delivery was greater among hypertensive patients (3.79+/-4.81Lt versus -0.70+/-0.72Lt, P<0.001).

CONCLUSIONS

Bioelectrical impedance analysis is a practical tool in the follow-up of anti-hypertensive therapy at term gestation. Moreover, nifedipine increases TBW in gestational hypertensive patients, reverting the pathophisiological pattern, yet described elsewhere.